The province of Britain remained very much as Agricola had left it, stopping short at the Forth, and leaving the Scottish Highlands outside the Roman pale. It was held down by three Roman legions, each of whom watched one of the three most unruly of the British tribes; one at Eboracum (York) curbed the Brigantes; a second at Deva (Chester) observed the Ordovices; and a third at Isca (Caerleon-on-Usk) was responsible for the good behaviour of the Silurians. Agricola did much to make the Roman rule more palatable to the Britons by his wise ordinances for the government of the province. He tried to persuade the Celtic chiefs to learn Latin, and to take to civilized ways of life, as their kinsmen in Gaul had done. He kept the land so safe and well guarded that thousands of settlers from the continent came to dwell in its towns. His efforts won much success, and for the future, southern Britain was a very quiet province. [Sidenote: =The Wall of Hadrian.=] But the Caledonians to the north retained their independence, and often raided into the Lowlands, while the Brigantes of Yorkshire still kept rising in rebellion, and once in the reign of Hadrian massacred the whole legion that garrisoned York. It was perhaps this disaster that drew Hadrian himself to Britain in the course of his never-ending travels. The emperor journeyed across the isle, and resolved to fix the Roman boundary on a line traced across the Northumbrian moors from Carlisle to Newcastle. There was erected the celebrated "Wall of Hadrian," a solid stone wall drawn in front of the boundary-ditch that marked the old frontier, and furnished with forts at convenient intervals. This enormous work, eighty miles long, reached from sea to sea, and was garrisoned by a number of "auxiliary cohorts," or regiments drawn from the subject tribes of the empire--Moors, Spaniards, Thracians, and many more--for the Romans did not trust British troops to hold the frontier against their own untamed kinsmen. The legion at York remained behind to support the garrison of the wall in case of necessity. [Sidenote: =The Wall of Antoninus.=] A few years later the continued trouble which the northern parts of Britain suffered from the raids of the Caledonians, caused the governors of the province to build another wall in advance of that of Hadrian. This outer line of defence, a less solid work than that which ran from Newcastle to Carlisle, was composed of a trench, and an earthern wall of sods, drawn from the mouth of the Forth to the mouth of the Clyde, at the narrowest part of the island. It is generally called the Wall of Antoninus, from the name of the emperor who was reigning when it was erected. [Sidenote: =Campaign of Severus in Caledonia.=]